Automatic switch.



0. E. RASMU SSEN.

AUTOMATIC SWITCH. APPLICATIONHLED SEPT-22,1916

Patented Nov. 5, 1918, 3 SHEETS-SHEET 1 kwanfor: Osva/a/ f. flasmuss n 0. E. RASMUSSEN.

AUTOMATIC SW ITCH.

APPLICATION FILED SEPT-22, l9l6.

1 383,894. Patented Nov. 5, 1918,

3 SHEETS-SHEET 2.

lnvenfok: I Qsv/a/d E. Ra's/270x50? by M 0. .E. RASMUSSEN.

AUTOMATIC SWITCH, APPLICATION FILED SEPT- 22. 19:6.

Patented Nov. 5, 1918..

3 SHEETS-SHEET 3.

ln 1 for: 0s va/a' E, fiasmqss en.

UNITED STATES PATENT OFFICE.

OSVALD E. RASMUSSEN, OF WEST HOBOKEN, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC SWITCH.

Patented Nov. 5, 1918.

Application filed September 22, 1916. Serial No. 121,569.

To all whom it may concern:

Be it known thatI, OSVALD E. RASMUS- SEN, a subject of the King of Denmark,

lowing is a full, clear, concise, and exact de-' scriptlon.

This invention relates to machine switches of the type employed in automatic telephone systems.

The invention has for its purpose the production of an automatic switch employing a minimum number of operating electro magnets, and which will be positive and accurate in operation and economical to manufacture.

The main feature of this invention is the use of mechanical means which permits the construction of an automatic switch having but a single operating magnet;

Other features of this invention will appear from the detail description and claims.

Figure 1 is a side elevation, partially in section, of the improved switch. Fig. 2 is a sectional view of the improved switch taken on the line 2-2 of .Fig. 1. Fig. 3 is a front view of the side switch employed in this switch. Fig. 4 is a sectional view taken on the line 4-4= of Fig. 1. Fig. 5 is a sectional view taken on the line 55 of Fig. 1. Fig. 6 is a detail view of the operating pawl and the shaft in their normal positions. Fig. 7 is a similar view of the operating pawl and shaft'in position for the primary or rotary movement. Fig. 8 is a similar view of the operating pawl, of the holding dogs, and the shaft,-showing the relation of these elements during the release of the switch. Fig. 9 diagrammatically illustrates acircuit arrangement suitable for operating the automatic switch of thisinvention.

.Referring in. detail to. the drawings, in the present arrangement a single motor magnet is employed. This motor magnet operates a shaft which-carries an operating pawl. This shaft is controlled-by slow-acting mechanism to properly positlon the operatin'gpawl for its several operations of I rotating, elevating'and restoring the shaft to its normal position.v

'10 designates a brushshaftmounted for vertical and rotary -movement in the supcharacter 11. The shaft is provided with movable terminals or brushes 13, which are posltioned to move into engagement with the passive contacts of the terminal bank 14. This brush shaft, at its intermediate portlon, is provided with a cylindrical portion 12, which is cut vertically and horizontally to provide vertical and rotary ratchet teeth.

, The controlling and operating mechanism of the switch is supported by a rectangular frame, carried by the supporting structure v11. This frame is composed of a U-shaped member 15, having its free ends bent at right angles, and a flat bar 16 secured to these over-turned ends. The sides of this frame have two sets of horizontally alining apertures. In one aperture of the lower set, there is journaled a bushing 17 to which is secured a gear wheel 18. This bushing is provided with a square opening to receive the squared portion of the shaft 19. The bushing cooperates with the other lower aperture in the frame to support the shaft c porting structure indicated by the reference 19 for longitudinal and rotary movement.

This shaft is also provided with a collar 20, the purpose of which will be herein later described. 'A spiral spring 21 surrounding the shaft 19 has one of its ends engage the frame and has its other end engage the col lar 20 to normally force the shaft .to the left. The right-hand end of the shaft 19 is rovided with an angular portion on which the actuating pawl 22 is pivotally mounted. An arm 23 secured to the angular portion operates in the release of the switch. The pawl 22 is provided with an angular extension 24 which engages a cam 25. This cam 25 is rigidly secured to the frame and serves to position pawl 22 into and outof engagement with the vertical and rotary ratchet teeth of'the shaft.

In the u per set of apertures a shaft26 is journale for rotary movement. The lefthand end of this shaft carries the movable brushes 27 of the side-switch structure des-- ignated, as a whole, by the reference character 28. A gear wheel 29 is secured to this shaft in alinement withgear wheel 18. A

ratchet wheel 30 is secured to the gear wheel 29 A second ratchet wheel 31, which is free to rotate on the shaft, is connected to the ratchetwheel 30 by means of the coil spring 32 A disk 33 also loosely mounted on the shaft, is provided with a milled edge with which the resilient pawl 31 is mounted to engage. This resilientpawl is carried by a U-shaped member 35, the free ends of which are apertured, to receive the shaft 26. One end of this U shaped member is extendedto engage an arm 36 of the bell crank lever. The other arm 48 of this lever is engaged by the collar 20 previously mentioned. Frame 35 carries a rod 37 on which there is pivotally mounted a pawl 38, which is positioned to engage the ratchet wheel 31. A holding pawl 49 (Fig. 5) carried by the frame, holds the ratchet wheel 31 in the position to which it has been actuated. The free end of the rod 37 engages a holding dog 39. This dog 39,as well as holding dog 40, are pivoted on the frame and are properly tensioned to normally engage the ratchet wheel 30.

The motor magnet 41 is secured to the supporting structure 11, and its armature 4:2 is mounted to engage the free end of the shaft 19.

An arm 43 pivotally secured to the frame is provided with a vertical holding dog flea and a rotary. holding dog 15. 46 deslgnates a stationary dog which serves to pre vent the shaft from rotating to its normal position after the first vertical step.

Referring to the operation, when the motor magnet 11 is first actuated, its armature 12 engages and forces the shaft 19 to the right. The collar 20 on the shaft engages the arm 18 ofthe bell crank lever. This causes the arm 36 of this lever to rotate the U-shaped frame 35. The frame 35 in advancing operates the pawl 38 and moves the ratchet wheel 31 one step. When the 'motor magnet deenergizes and retracts its armature, the spring 21 forces the shaft 19 to the left, which permits the arm 36 to disengage the U-shaped frame 35. Frame 35, under the action of its retractilc spring, proceeds to return to its normal position. The resilient pawl 34, however, engages the milled edge of disk 33 and the inertia of this disk does not permit frame 35 to return rapidly. If now the motor magnet 41 is again immediately energized, the frame 35 and the driving pawl 38, will not be restored. The pawl 38 will not engage a second tooth of the ratchet wheel but will continue to ride on the face of the tooth previously engaged. When, however, the motor magnet 4E1 retracts its armature for a relatively long interval, corresponding to the interval between successive digits of the desired number, or to the interval between the selecting and hunting movement of the switch, the frame 35 will return mal position.

Rod 37 carried by the frame 35 disengages the holding pawl 39 (Fig. 1) from the to its nor- I sition, finder ratchet wheel 30. The coil spring 32 then causes the ratchet wheel 30 and the gear wheel 29 carried thereby to rotate a distance corresponding to one tooth of the ratchet wheel. The gear wheel 30 engages and operates gear wheel 18 to rotate the shaft 19 through one quarter of a revolution. Th pawl 22 will then be rotated to its first actuating position, which, in the switch shown, is the primary or rotary movement. Simultaneously the shaft 19 and the movable brushes of the side-switch are rotated to their next posititon to com plete operating circuits in the well-known manner. On the next actuation of armature 412 of the motor magnet, the shaft 19 and the pawl 22 carried thereb moye the shaft in a rotary direction. At the close ofthe first series of impulses the slow-acting mechanism again rotates the shaft 19 through a quarter of a revolution to position the driving pawl 22 as shown in Fig. 1 of the drawing. At the close of this series of impulses, the shaft 19 will be rotated through a quarter of a revolution to position the pawl 22 and the arm 23 as indicated in Fig. 8 of the drawings. It will here be noted that the cam 25 engages the angular extension 24L of the actuating pawl to move the pawl out of engagement with the ratchet wheel against the tension of the retracted spring. In this position of the arm 23 when the shaft is caused to rotate, the holding dogs 4A and 45 release the shaft, permittting it to descend. When the stationary dog 16 disengages the ratchet teeth, the shaft is rotated to normal position by the actuated coil spring 47. At the close of this operation the shaft 19 again is rotated to position the actuating pawl as indicated in Fig. 6 of the drawing. It should be noted that the brushes 27 of the side switch 28 always move in the same rotary direction. This arrangement obviates the need for retractile springs and escapement elements now used in devices of this type.

The switch is described as having first a rotary and then a vertical movement of its brush shaft, but it will be readily understood that this invention will be equally effective in switches having first a vertical and then a rotary movement;-

Referring to Fig. 9, when the subscriber, whose substation apparatus is indicated A, removes his receiver from the switchhook, brushes 50, 51 and 52, of a well-known line finder (not shown) locate the terminals of the calling line and extend this line to a selector switch of the type herein disclosed. A stepping relay 5 3.associated with this selector is energized over a circuit which may be traced from grounded battery, stepping relay 53, side-switch wiper 54 in its first pobrush 51 and its contact, substation apparatus A, contacts of the sending device, brush 50, side-switch arm 64 to ground Stepping relay 53 attracts its armatures and at its left-hand armature momentarily completes an operating circuit for magnet 41. The motor magnet attracts its armature 42 and thereby actuates the slowacting mechanism of the switch. Since impulses are not immediately transmitted to magnet 41, the side switch is rotated to lts second position. Simultaneously the shaft 19 is rotated to position the pawl 22 as shown in Fig. 7 for the primary movement of the switch.

The switch is now in position to receive the directive impulses from the calling dial. The circuit for the stepping relay 53 now extends through the second position of sideswitch wipers 54 and 64. The operating circuit for the motor magnet 41 now extends from grounded battery, magnet 41, side-switch wiper 55, in its second position, conductor 56, left-hand armature and back contact of stepping relay 53 to ground. The

subscriber at A now operates his sending device to advance the switch in the wellknown manner.

At the close of this series of impulses the side-switch wipers are rotated as above described into their third position, whereupon a self-interrupting circuit for the motor magnet 4]. is completed from grounded battery, magnet 41, side-switch wiper 55 in its third position, armature and back contact of magnet 41, conductor 56, left-hand armature and back contact of stepping relay 53 now deenergized to ground. The brushes 57, 58 and 59 are moved over the terminals of the trunks of the group until an idle trunk is located. This idle condi tion is indicated by ground on the test terminal 60. When the test brush 59 encounters the grounded test terminal 60, stepping relay 53 is again energized, and at its left-- hand contact interrupts the operating circuit just described for the magnet 41. The

side-switch wipers thereupon rotate into their fourth position.

In this position of the side-switch wipers, a circuit is completed to the test contact from which the ground is now removed, for the motor magnet, which may be traced from grounded battery, magnet 41, sideswitch wiper 55 in its 4th position. contact spring 61 and its back contact, right-hand armature and back contact of stepping relay 53, side-switch wiper 62 in its 4th position, test brush 59 and test contact 60.

At the termination of the conversation,

- when the calling party replaces his receiver,

ground is restored to the test contact and the motor magnet is energized over the circuit just described. The magnet 41 attracts its armatures, and establishes a locking circuit for itself, which may be traced from grounded battery, magnet 41, side-switch wiper 55 in its 4th position, contact spring 61, right-hand armature and front contact of magnet 41, ofi normal contact 63 to ground. The holding dogs 44 and 45 are withdrawn and the shaft is returned to normal as previously described, and as shown in F ig. 6.

It will be understood that the present disclosure is merely illustrative of applicants device, and that the scope of the present invention is to be limited only by the appended claims.

What is claimed is:

1. In anautomatic switch, passive contacts, active contacts mounted for group and line selecting movements, and a single means for actuating and for controlling the nature of the movements of said active contacts. p 2. In an automatic switch, passive contacts, active contacts mounted for group and line selecting movements, and a single means for actuating, for controlling the nature of the movements and for restoring said active contacts to normal position. I

3'. In an automatic switch, passive con tacts, active contacts, a shaft to which said active contacts are secured, said shaft being mounted for movement in two directions, an operating element mounted to actuate said shaft in its several movements, and a single means to actuate and control the character of movements of said operating member.

4. In an automatic switch, passive contacts, active contacts, a shaft to which said active contacts are secured, said shaft being mounted for movement in two directions, a pawl mounted to actuate said shaft in its several movements, and means to actuate said pawl.

5. In an automatic switch, passive contacts, active contacts mounted for movement in two directions, anda single mechanically controlled means for controlling the nature of the movements of and for restoring said active contacts to normal position.

6. In an automatic switch, passive contacts, active contacts mounted for group and line selecting movements, a single means for actuating said active contacts, and a circuit controlling device mechanically controlled by said actuating means.

In witness whereof, I hereunto subscribe my name this 20th day of September, A. D. 1916.

"OSVALD E. RASMUSSEN. 

